Anti-pendulum crane rigging



June 29, 1965 J. S- THOMSON ANTI-PENDULUM CRANE RIGGING Filed July 9, 1953 I n ven [or Joy/v Jrimvsozv 771mm) Attorney United States Patent Office 3,191,779 Patented June 29, 1965 3,191,779 ANTi-PENDEJLUM (ZRANE RIGGKNG Eolin S. Thomson, 154 Forsyth t., Green-oak, Scotland Fiied July 9, 1963, Ser. No. 293,797 Claims priority, application Great Britain, duly 18, 1962, 27,534/62 2 Claims. (til. 21258) This invention relates to cranes, particularly but not exclusively to ships cranes in which the load is suspended by a winch rope from a pulley on a jib which jib can be slewed and/or lufied with respect to the ships deck.

In use of such cranes when a load is slewed to one side or the other, say in a horizontal plane, and the slewing motion of the jib ceases, the load will continue in its horizontal direction and will thereafter swing pendulously unless provision is made to stop such swinging, which may be dangerous. It is known to provide pull ropes which are attached to the load and depend freely therefrom, such ropes being pulled by workmen in opposition to the instantaneous direction of pendulous swinging. Undesirable pendulous motion also occurs when the jib is luifed.

It is an object of the present invention to provide simple and inexpensive means devised to minimise and dampen pendulous swinging of the load automatically when the jib is slewed or luffed.

According to the present invention there is provided a crane including a winch having at least one winding drum, a jib adapted to be pivotally mounted on the deck of a ship for lufling and slewing movements, first pulley means attached to the outer end of said jib, an outrigger mounted on the jib and extending to opposite sides thereof, two second pulleys mounted on the outrigger on opposite sides of the jib, a load supporting rope, a load pulley block supported by said rope, said rope having its free ends wound round the winding drum in the same direction, the rope then passing in parallel reaches from the winding drum and then round the first pulley means, downwardly to the pulley block and therearound and thereafter the reaches diverge upwardly and form a loop passing over the second pulleys.

An embodiment of the invention will now be described, by way of example, with reference to the accompanying drawing, in'which:

FIG. 1 is a perspective view of a crane illustrating the invention.

Referring to FIG. 1, a crane is mounted on a ships deck and includes two upright columns 10, 1% secured to the deck and connected at their top ends by a cross member 11, said cross member mounting a medial stationary pulley block 12. Also mounted on the deck is a winch 13 and a flanged pivotal support 14 midway between the columns to which is attached a jib 15 so that said jib is adapted for luffing and slewing movement with respect to the ships deck. At its outer end the jib 15 mounts first pulley means in the form of two similar pulley blocks 16, 16 each having two pulleys. Disposed generally at the outer end of the jib 15 is secured a transverse frame indicated at 17 which comprises two arms 18, 18 which extend oppositely and outwardly from the jib 15, each of said arms 18, 18 mounting second pulley means 19, 19 on opposite sides of the jib 15.

A suspended pulley block 20 forms a point of load attachment for the crane, said suspended pulley block 20 being supported by load supporting rope means 21. The term load supporting rope means when used hereinafter and in the claims is intended to embrace fibre rope, wire rope and any other known elongated load supporting member. The load supporting rope means 21 comprises a single length of rope having free ends which are wound round a winding drum 22 of the winch 13 in the same direction, so that as the winding drum 22 rotates both ends of the rope are fed out or wound in depending on the direction of drum rotation. The rope is led from the winding drum 22 to the pulley block 16, 16 by way of the medial stationary pulley block 12 and therearound, then downwardly to the pulley block 20 and thereafter in a loop round the second pulley means 19, 19, so that the suspended pulley block 20 is supported by mutually converging rope reaches 21'.

In order that heavy loads (for example over 5 tons) may be lifted the winding drum 22 may be provided in two parts, one end of the rope wound round one part of the drum and the other end wound round the other part of the drum, both parts being selectively windable while the other part is held, that is the rope may be wound in on one part of the drum, thus providing a lower velocity ratio of lifting.

In operation, when a load is attached to the suspended pulley block 20 and the jib 15 is slewed from one place to another and then stopped, any tendency of the load to swing pendulously is dampened by the mutually converging reaches of rope which automatically pull against the instantaneous direction of load swinging.

Modifications may be made in respect of the above embodiment, for example several winding drums may be provided in order to attain diiferential feeding or winding of the ropes, in order to meet particular requirements.

I claim:

1. A crane including a winch having at least one winding drum, a jib adapted to be pivotally mounted on the deck of a ship for lufling and slewing movements, first pulley means attached to the outer end of said jib, an outrigger mounted on the jib and extending to opposite sides thereof, two second pulleys mounted on the outrigger on opposite sides of the jib, a load supporting rope, a load pulley block supported by said rope, said rope having its free ends wound round the winding drum in the same direction, the rope then passing in parallel reaches from the winding drum and then round the first pulley means, downwardly to the pulley block and therearound and thereafter the reaches diverge upwardly and form a loop passing over the second pulleys.

2. A crane according to claim 1 including two upright columns, a cross member joining the upper ends of said columns, a supporting pulley block supported on said cross member, and the parallel rope reaches being trained round said supporting pulley block before passing to said first pulley means.

References Cited by the Examiner UNITED STATES PATENTS 3,062,383 11/62 Claesson 21258.1 3,065,862 11/62 Patterson 21258.1 3, 107,791 10/ 63 Michael 2125 8.1

OTHER REFERENCES German provisional specification 1,112,270, published Aug. 3, 1961.

SAMUEL F. COLEMAN, Primary Examiner.

ANDRES H. NIELSEN, Examiner. 

1. A CRANE INCLUDING A WINCH HAVING AT LEAST ONE WINDING DRUM A JIB ADAPTED TO BE PIVOTALLY MOUNTED ON THE DECK OF A SHIP FOR LUFFING AND SLEWING MOVEMENTS, FIRST PULLEY MEANS ATTACHED TO THE OUTER END OF SAID JIB, AN OUTRIGGER MOUNTED ON THE JIB AND EXTENDING TO OPPOSITE SIDES THEREOF, TWO SECOND PULLEYS MOUNTED ON THE OUTRIGGER ON OPPOSITE SIDES OF THE JIB, A LOAD SUPPORTING ROPE, A LOAD PULLEY BLOCK SUPPORTED BY SAID ROPE, SAID ROPE HAVING ITS FREE ENDS WOUND ROUND THE WINDING DRUM IN THE SAME DIRECTION, THE ROPE THEN PASSING IN PARALLEL REACHES FROM THE WINDING DRUM AND THEN ROUND THE FIRST PULLEY MEANS, DOWNWARDLY TO THE PULLEY BLOCK AND THEREAROUND AND THEREAFTER THE REACHES DIVERGE UPWARDLY AND FORM A LOOP PASSING OVER THE SECOND PULLEYS. 